Fluid machine



Nov. 28, 1967 H. HORNSCHUCH 3,355,097

FLUID MACHINE Filed Dec. 22, 1965 2 Sheets-Sheet l 7 5; INVENTOR HANNS HO/P/VS CHUCH 9 :y w. "PW

ATTORNEY Nov. 28, 1967 HORNSCHUCH I 3,355,097

FLUID MACHINE Filed Dec. 22, 1965 2 Sheets-Sheet 2 z; I E /f E 75' 15/ 5/ Zj/ a; I w r if f/ IIIIIIIIIIIIIIIIIIIIIII" 3 HA/VNS HORNSCHUCH ATTORNEY United States Patent 3,355,097 FLUID MACHINE Harms Hornschuch, Easton, Pa, assignor to lngersoll- Rand Company, New York, N.Y., a corporation of New Jersey Filed Dec. 22, 1965, Ser. No. 515,559 9 Claims. (Cl. 230209) ABSTRACT OF THE DISCLOSURE A multi-stage compressor package which is enclosed within a casing formed by a pair of separable casing members; and a centrifugal pump assembly for such a compressor package which includes an axial inlet, an outlet surrounding the inlet and coaxial therewith, heat exchange means disposed in the outlet, and moisture separator means disposed in the outlet downstream of the heat exchange means.

The disclosure This invention is concerned with fluid pumps. In particular the invention is concerned with a multi-stage air compressor package wherein the exhaust or compressed air from each compression stage is cooled prior to its entry into the next succeeding stage and prior to its final discharge from the compressor package.

Specifically, the invention is directly concerned with, and represents an improvement over, the single motor driven, multiple pump, multi-stage compressor packages of the type shown in United States Patent No. 3,001,692, issued Sept. 26, 1961, to Schierl.

As is known in the art, the efficiency of any compressor, and particularly a multi-stage compressor, is increased greatly by cooling the air between each progressive stage of compression. However, the incorporation of this desirable feature in multi-stage compressor packages has led to many complications including manufacturing difficulties, increased costs, and inconvenience and inefiiciency arising from the use of a myriad of external components such as external coolers, valves and air and water piping. For these reasons, compressor packages of this type generally have not met with particular favor even if more efficient than the non-cooled type of unit.

The present invention has for an object the provision of an efiicient multi-stage compressor package.

A further object of the invention is to provide a highly efficient multi-stage compressor package which is free from external components, yet which provides for adequate cooling of air between compressor stages.

An additional object of the invention is to provide an economically manufactured multi-stage compressor package.

Still a further object of the invention is to provide a novel intercooler-pump assembly adapted particularly for use in multi-stage compressor packages while being capable of single stage use where desired.

These and other objects of the invention not specifically referred to, but inherent therein and apparent to those skilled in the art, many be accomplished by providing a closed casing; an inlet port and an outlet port in said casing; centrifugal pump means within the casing; means serially interconnecting said pump means between the casing inlet and outlet such that air from said inlet is directed serially through said pump means and then discharged through said outlet, said interconnecting means being comprised of a manifold assembly incorporated in the casing and in communication with the inlet and outlet of each serially connected pump; cooling means in heat exchange relation with the outlet of each pump and 3,355,697 Patented Nov. 28, 1967 common drive means for driving all of said serially connected pumps from a single prime mover.

Preferably, each centrifugal pump assembly comprises impeller means; a cylindrical, co-axial inlet means leading to said impeller means; concentric cylindrical outlet means surrounding the cylindrical inlet means; diifuser means directing air from said impeller to said outlet means and cooling means disposed between the co-axial and cylindrical walls of the inlet and outlet means, said cooling means comprising a plurality of heat exchange tubes disposed axially parallel to each other and the center of the inlet and outlet means; header plates supporting the tube ends and defining with the walls of said cylindrical inlet and outlet means a sealed coolant chamber surrounding said tubes. It is also contemplated that water separation means be disposed on the outlet side of the compress-or stages, same being also doughnut shaped and between the walls of the inlet and outlet means.

Having described in broad terms the basic concepts of the invention, the application and structural details thereof will become apparent from consideration of the descriptive matter which follows and the drawings forming a part thereof, wherein:

FIG. 1 is a perspective view showing a compressor package, same in this case having hinged casing or hous-v ing parts and being shown opened as when being serviced.

FIG. 2 is an elevational sectional view of a pump unit.

FIG. 3 is a sectional view taken along the line 33 of FIG. 1 and showing the port arrangement within the hinged casing part.

FIG. 4 is a view similar to FIG. 3 and taken along the line 44 of FIG. 3, to show additional port details.

FIG. 5 is a sectional view taken along the line 5-5 of FIG. 2 and showing the interior detail of a heat transfer tube, and

FIG. 6 is a view similar to that of FIG. 3, but taken along the line 6-6 of FIG. 4.

As shown in FIG. 1, a multi-stage compressor package made according to the invention comprises a casing structure including a stationary casing member 10 and, in this instance, a swingable casing member 20 hinged thereto at hinge 1. It will be appreciated that in some instances the hinge 1 may not be used, in which case the casing member 20 would simply be removable from the casing member 10. Thus, as the casing members It), 20 may be either hingedly or merely detachably connected, it will be understood that hereinafter the terms swingable and removable are used interchangeably to indicate that casing member 20 is movable with respect to casing member 10. The stationary casing member 10 rests on supporting feet 3, 3 which are attached to a motor base 5. Mounted on base 5 is a prime mover 7, in this case an electric motor, although it will be appreciated that other prime movers, such as an internal combustion engine, can also serve equally well. The prime mover is connected by a gear train (not shown), housed within the back of casing member 10, to a plurality of pump units or assemblies 30 which units will be described later. The gear train arrangement, purely conventional in the art, is so arranged as to drive the units 30 simultaneously. Each unit 30 is mounted on the face of a vertical back plate 9 provided at its center with an internally threaded button 11 which receives a central clamping bolt 13 carried by the swingable casing member 20. It will be noted that the units 30 are so arranged as to project outwardly somewhat beyond the vertical plane in which the flanged edge 15 of casing 10 is disposed.

With particular reference to the swingable or movable casing member 20, it will be seen that same is generally dome shaped and also is provided with an interior vertical wall 17 recessed inwardly away from the vertical plane of the edge flange 19 of this member. Wall 17, hereinafter called a manifold wall, is provided with groupings of ports 21; each group including a central opening hereinafter referred to as a sun port surrounded by angularly spaced ports having their centers lying in a concentric circle around the sun port, and hereinafter called satellite ports, the function of same to be described later.

The arrangement of manifold wall 17, within casing member 20, is such that when same is swung closed or otherwise positioned against stationary casing member and flanges and 19 bolted together, along with threaded engagement of bolt 13 in button 11, the ends of pump units 30 are in face to face contact with wall 17. Suitable gasket means, not shown, but of conventional materials and construction, may be interposed between the ends of pump units 30 and manifold wall 17 so that there is a complete sealing between the ends of the units and the wall and there is no communication between units 30 and the space defined between manifold wall 17 and back plate 9.

It will also be noted that the upper ends of the casing members 10 and 20 are provided with paired and intercommunicating ports 23, 25, 23', 25', respectively. These ports define air inlet and outlet ports which, as will be described, are suitably placed in communication with pump units through the manifold portion of easing member 20 behind manifold wall 17.

With the over-all construction of the present invention in mind, attention is now directed to FIG. 2, illustrating a preferred pump unit structure. As shown, back plate 9 is provided with an aperture 29 provided with any form of suitable bushing or bearing member 31. A shaft 33, driven from the mentioned gear train, projects through the opening and terminates in a threaded end receiving nut 35. A conventional centrifugal impeller 37 is keyed on shaft 33. Extending behind the impeller and fixed to the back plate 9 by bolts 39 is a diffuser spider 41 which contains the impeller and includes passages 43 leading outwardly from the periphery of impeller 37. The central portion of the diffuser spider 41 is open at 47 whereby fluid, in this case air, is drawn in axially toward, and centrally of, the impeller and discharged outwardly wherein the shape of passages 43 re-directs flow away from the impeller in a direction parallel to the axis of rotation of the impeller 37. In sealing abutment with the diffuser spider 41 is an elongated inlet cylinder 51 having structural means 53 and 54 whereby its inner terminal end may be mated against the spider 41. Surrounding inlet cylinder 51 and having an intermediate, outwardly extending flange 65 by which it may be bolted by stay bolts 67 into edge abutment with back plate 9 is an outlet cylinder 63. This outlet cylinder serves along with passages 43 to redirect air from impeller 37 out of the pump unit 30 in a gi7rection parallel to the axis of rotation of the impeller As stated, the efiicency of an air compressor, particularly a multi-stage compressor, can be improved if, at each stage, the outlet air is cooled to remove the heat of compression developed within the compressor. To this end, it will be seen that the outlet duct 59 formed between cyllnders 51 and 63 is provided with heat exchanger 70. The heat exchanger 70 is comprised of doughnut shaped headers 55 and 57 sealingly in engagement with the outer surface of cylinder 51 and the inner surface of cylinder 63. The headers are pierced at angularly spaced points around the annular outlet chamber 59 and receive in angularly spaced, parallel relation a plurality of tubes 71. The tube ends are swaged or otherwise locked into immobile relation in the pierced headers 55 and 57, as is conventional practice in the art. Thus air exiting from the impeller 37 is caused to pass through tubes 71 and, if the coolant chamber 72 surrounding the tubes is filled with a suitable coolant fluid, such as water flowing therethrough, the air will be cooled prior to its exit from pump unit 30.

Turning now briefly to FIG. 5,a preferred form of heat exchange tube is shown in section. As illustrated, the center of the tube contains a small diameter core 73 of a good heat conductive metal. Surrounding the core 73 is a fluted fin element 75 formed so as to contact both the inner surface of tube 71 and the outer surface of core 73 in heat exchange and core supporting relationship. Thus the air passing through the tube will, by conduction of core 73 and fin 75, carry heat outwardly to the tube wall where it is carried to the coolant surrounding the tube.

Immediately succeeding the heat exchanger 70 is a doughnut shaped separator 80. Separator is comprised of annular, axially spaced, concentric frame members 82, 84 having therebetween a vapor entrapping material such as stainless steel crinkle mesh 86, and perforated or screen type of face plates 88, 88. During the operation of the separator 80, the crinkle mesh 86, as will be understood. tends to separate and condense water vapor entrained in the compressed gas emitted from the intercooler 70. Suitable drain means, designated generally as 90 in both FIGS. 1 and 2, is provided to convey the water from separator 80 outside of the casing structure 10.

Referring again to FIG. 1, it will be seen that each pump unit 30 is disclosed as being identical as to over-all operation and general structure, though there may be variations in capacity between the units, and that if outlet air is properly conducted from inlet 23 through each unit 30, successively, and then to outlet 25' in casing 10, a very simply maintained, highly efficient multi-stage compressor package can be produced.

To accomplish this result, the outlet passage 59 of each unit 30 is in cimmunication with the satellite ports of one of the port groups 21 in manifold plate 17, while the inlet cylinder 51 of each unit 30 is in communication with the central or sun port of such group of ports.

These port groups 21, in turn, are suitably arranged in manifold wall 17 so that casing member 20, in effect, acts as a manifold system directing the fluid from inlet 23 through the successive pump units 30 and then to outlet 25. One manner of forming a manifold system is illustrated in FIGS. 3 and 4 wherein the manifolding or ducting of the casing member 20 is shown as fabricated of welded components.

As shown in FIG. 3, air from inlet 23' in stationary casing member 10 enters the casing member 20 through inlet 23 and thence flows into an upper inlet chamber 81 which is defined by the end wall 83 of easing member 20, a horizontal dividing wall 85 and a vertical duct wall disposed parallel to, but spaced from, manifold wall 17. From chamber 81 the fluid enters the upper right hand pump unit 30 (as viewed from the motor end of casing member 10) through the sun port 87 of upper right hand port group 21 in casing member 20. After passage through pump unit 30 the fluid is exhausted through satellite ports 89 into upper outlet chamber 91, formed above divider wall 186, and thence flows through and via an opening 93 into lower inlet chamber 95 where it enters the second stage pump unit 30, at the lower right hand side of casing 10, via lower inlet duct 97.

As shown in FIGS. 3 and 4, the inlet chamber 95 is formed by end wall 83 of casing 10, duct wall 90, horizontal divider wall 85 and the lower portion of an additional divider wall 99 which is located on a vertical diametric line and extends completely from top to bottom of casing member 20. Thus fluid discharged from the second pump unit 30 must pass across this wall to reach the third and lower left hand pump unit 30. As shown in FIG. 6, this is accomplished via port 101 which permits second stage discharged air to enter chamber 103 in the lower left hand quadrant of the swingable casing member 20, said chamber being defined by manifold wall 17, duct wall 90, the exterior wall of easing member 20 and a further horizontal divider wall 102. Air enters the inlet port (not shown), leading to the lower left hand pump unit 30, is compressed, and then discharged through extensions 196 of the satellite ports, which exhaust into chamber 110. The chamber 110, as illustrated in FIG. 6, is defined by the casing wall 83, vertical divider wall 99 and a further horizontal divider wall 107, which, with duct wall 90, forms a closed chamber provided with an outlet port 109 which feeds air from third stage pump unit 30 to the fourth and final unit disposed in the upper left hand side of easing member 10.

Air flows from port 109 into chamber 111, defined between walls 17, 102 and 90, and thence into the inlet port (not shown), of the fourth stage pump unit 30. Compressed air discharged by this pump unit 30 flows through the satellite port extensions 116 into chamber 113 which directs it to the outlet passage 25 in swingable casing member 20 from whence it flows to the outlet port 25 in casing member and is discharged from the compressor.

While, as shown, the manifold system is fabricated of suitably welded chambers, ports and baffles, it will be appreciated that same can be incorporated in the movable casing member by forming the casing member as a cast unit with the porting means incorporated therein during the casting process. This latter arrangement, which will be simpler and more economical to produce, is particularly attractive for use in, for example, compressor packages of a capacity having the most general industry utility and subject to repetitive manufacture, as distinguished from special order items, that is items of very high capacity suitable for a particular or peculiar industrial application not likely to be repeated. In either case, whether cast or fabricated, the porting arrangement will be such as to isolate the output of each stage from the output of any other stage so that passage of the fluid or gas is successive through the compressor stages.

The many advantages of the described multi-stage compressor package will now be apparent. For example, movable casing member 20 defines essentially a manifold for conducting air or other fluid from stage to stage or successively to and through the pump units 30. Thus this casing member contains no working parts and may easily be made swingable about hinge 1, where used, or easily removed from casing member 10 where same is not hingedly connected to casing member 10. Secondly, each pump unit 30 with its associated intercooler is easily serviced with the casing open. All components are so affixed to wall 9 of the stationary casing member 10 as to be easily and readily removed for servicing. Further, all external components are eliminated. The only connection external of the casing members are to the compressor package inlet 23' and the outlet 25, a coolant water inlet 120 and outlet 130 whereby coolant water is carried through pump units 30 via conduits 125 to fill intercooler chambers 72 and drain 90 from the moisture separators 80. It will be understood that cooling water flow and, if necessary, water removal from the drain 90 may be readily accomplished by readily available and conventional pump means.

It will be appreciated that various arrangements for directing cooling water from and to the respective pump units 30 are possible, the selected arrangement being such as to produce the desired degree of cooling at each stage. Hence the system shown in FIG. 1 is exemplary only and should be so considered.

Having, then, described the invention in detail, it will be apparent that changes and modifications may occur to those skilled in the art, but that such modifications and changes are within the spirit and scope of the invention which is limited only as defined in the appended claims.

What is claimed is:

1. An air compressor comprising a casing having an inlet and an outlet, centrifgual pump unit means disposed within said casing, means serially connecting said pump unit means between said casing inlet and outlet such that said pump unit means compress the air in successive stages, means disposed within the outlet of each pump unit means for cooling the air compressed in each pump unit means before its entry into the next succeeding pump unit means, and water separation means disposed in the outlet of each pump unit means, all of said means being totally enclosed within said casing.

2. An air compressor comprising a casing including two separable members and having an inlet and an outlet, centrifugal pump unit means disposed within said casing, means serially connecting said pump unit means between said casing inlet and outlet such that said pump unit means compress the air in successive stages, said serial connecting means being completely housed in one of said casing members, and means disposed within the outlet of each pump unit means for cooling the air compressed in each pump unit means before its entry into the next succeeding pump unit means, all of said means being totally enclosed within said casing.

3. An air compressor as defined in claim 2 wherein said casing members are hingedly interconnected.

4. An air compressor as defined in claim 2 wherein said one of said casing members is movable relative to the other of said casing members, and wherein said pump unit means is comprised of a plurality of individual pump and intercooler assemblies disposed within said other of said casing member and having inlet and outlet means sealingly engaged with said serial connecting means contained in said one of said casing members.

5. A multi-stage air compressor comprising a closed casing including a stationary casing member and a removable casing member connected to said stationary casing member, an inlet port and an outlet port in said casing, centrifugal pump means disposed within the stationary casing member, said removable casing member comprising a manifold for serially connecting the pump means between said inlet port and said outlet port in said casing for communicating such inlet port and such outlet port with the inlet and outlet of each pump, cooling means in heat exchange relationship with the outlet of each pump within the casing and common drive means for powering all of the pumps simultaneously.

6. A compressor as defined in claim 5 wherein said pump means is comprised of a plurality of substantially identical pump assemblies, each of said assemblies including an outlet intercooler integrated therein and a moisture separator disposed downstream of said outlet intercooler.

7. For use in a multi-stage compressor package including a casing and a duct system for serially directing air through successive compression stages; a pump assembly, said pump assembly including an impeller; a diffuser spider containing said impeller; an inlet means associated with said diffuser spider for supplying air to said impeller in a direction co-axial with the axis of rotation of said impeller; an outlet means surrounding said inlet means; passage means formed within said diffuser spider for communicating said outlet means with said inlet means; heat exchanger means disposed within said outlet means; and a fluid separator disposed in said outlet means for separating entrained moisture from the air after its flow through said heat exchange means.

8. A centrifugal pump assembly comprising an impeller; a diffuser spider containing said impeller; inlet means arranged to supply fluid to said impeller in a direction co-axial with said impeller; outlet means surrounding said inlet means; means for communicating said outlet means with said inlet means such that fluid discharged from said impeller is discharged through said outlet means; heat exchange means disposed within said outlet means peripherally of said inlet means; and moisture separator means disposed in said outlet means downstream from said heat exchange means.

9. A centrifugal pump assembly as defined in claim 8 wherein said moisture separation means is comprised from 7 8 frame members, and a plurality of doughnut shaped face 2,518,246 8/1950 Morris 230209 plates, said frame members and said face plates defining 3 001 92 9 19 1 Schierl 230-209 a chamber; an air permeable mass within the chamber and drain means for carrying fluid away from said mass. 3211362 10/1965 Laskey et a1 230 209' References Cited 5 DONLEY J. STOCKING, Primary Examiner. UNITED STATES PATENTS HENRY F. RADUAZO,Examiner.

1,265,650 5/1918 Graemiger 230-209 

1. AN AIR COMPRESSOR COMPRISING A CASING HAVING AN INLET AND AN OUTLET, CENTRIFUGAL PUMP UNIT MEANS DISPOSED WITHIN SAID CASING, MEANS SERIALLY CONNECTING SAID PUMP UNIT MEANS BETWEEN SAID CASING INLET AND OUTLET SUCH THAT SAID PUMP UNIT MEANS COMPRESS THE AIR IN SUCCESSIVE STAGES, MEANS DISPOSED WITHIN THE OUTLET OF EACH PUMP UNIT MEANS FOR COOLING THE AIR COMPRESSED IN EACH PUMP UNIT MEANS BEFORE ITS ENTRY INTO THE NEXT SUCCEEDING PUMP UNIT MEANS, AND WATER SEPARATION MEANS DISPOSED IN THE OUTLET OF EACH PUMP UNIT MEANS, ALL OF SAID MEANS BEING TOTALLY ENCLOSED WITHIN SAID CASING. 